The purpose of this study is to obtain a substantial body of information about the pain experience in children, the long-term goal being to enable pediatricians, dentists, nurses, psychologists, and other adults involved with children to make more informed decisions concerning certain aspects of pain management. The study will focus on the knowledge and experience of acute and chronic pain in physically well and also hospitalized 5- to 12-year-old children (n equals 720). On the basis of the following criteria the children will be assigned to four groups: physically well, only hospitalization at birth; physically well, prior but not recent hospitalization; well enough to be home, recent minor surgery; and chronic ailment with one or more prior hospitalizations, currently hospitalized or requiring regular hospital treatment. An interview schedule will be developed to obtain the following information: The specific pain experiences of these children, their pain language, their reactions to pain, their coping strategies, their general knowledge of the topic of pain, and their sources of information about pain other than direct experience. This study should make two contributions that could result in a significant improvement in the management of children in pain or those about to undergo a painful procedure. It will provide a substantial body of information about the pediatric pain experience and will make available an interview schedule for assessing the individual child's knowledge and experience with pain. Neither the information on pediatric pain nor an adequate assessment tool is presently available to the research and clinical community.